1. Field of the Invention
The present invention relates to a hair cosmetic composition which imparts an excellent tactile feel to the hair and which suppresses or reverses damage to the hair.
2. Description of the Related Art
Recently, with the indivisualty of fashion, long hair has become increasingly popular. In addition, beauty treatments such as partial permanents have brought variations to hairdos of long hair. On the other hand, hair damage such as split hairs and broken hairs have increased. Such hair damage is considered to be caused by chemical treatments such as permanents which denature the keratinous protein of the hair to weaken the inside structure of the hair fibers and render the hair fibers vulnerable to mechanical forces applied when the hair is dried with a drier or is brushed.
In order to prevent hair from being damaged, it has been attempted to avoid degradation of the protein structure caused by chemical treatments by incorporating collagen, keratin proteins, and similar substances into hair care compositions to form a protective film on the surface of hair fibers, to impart moisture-retainability to hair fibers, or to enhance the elasticity of hair fibers (see, for example, Japanese Patent Application Laid-open (kokai) No. 61-280,413). Alternatively, it is also known to incorporate oily ingredients such as higher alcohols, ester oils, liquid paraffins, or silicone oils into hair rinses, treatments, brushing agents, setting agents, etc. in an attempt to reduce friction on the surface of hair fibers. However, hair care compositions containing collagen, keratinous proteins and the like do not sufficiently prevent damage to the hair. Furthermore, products containing oily ingredients are not sufficiently effective in reducing friction, and if the amount of incorporation of the oily ingredients is increased with an aim to improve their effect, the composition causes an unpleasant stickiness or greasiness.
Hair care compositions which contain polymer emulsions as a hair conditioning agent are known to solve the above problems (Japanese Patent Application Laid-open (kokai) No. 62-63,508). Polymer emulsions ensure adsorption of fine particles of the polymer onto hair fibers. Therefore, larger amounts of the polymer can be adsorbed compared to a low molecular weight hair conditioning agents which are adsorbed onto hair fibers as molecules, resulting in greater effectiveness. Polymer emulsions, however, have the drawback that they do not have selectivity when adsorbed onto hair fibers. They are adsorbed not only by damaged hair (hair fibers from which cuticles are scaled off), but also by healthy hair. If a polymer emulsion is adsorbed by healthy hair, the smooth tactile feel which the hair inherently possesses and natural texture of the hair are lost. This problem is more prominent when polymer emulsions are used than when low molecular weight hair conditioning agents are used, because polymer emulsions are adsorbed in larger amounts.
As described above, conventional hair cosmetic compositions do not necessarily provide satisfactory effects. Especially, most of them have insufficient damage prevention or restorative effects.